EP3496611A1 - Dispositif de capteur et procédé, dispositif et procédé de communication avec le dispositif de capteur. - Google Patents

Dispositif de capteur et procédé, dispositif et procédé de communication avec le dispositif de capteur.

Info

Publication number
EP3496611A1
EP3496611A1 EP17751076.5A EP17751076A EP3496611A1 EP 3496611 A1 EP3496611 A1 EP 3496611A1 EP 17751076 A EP17751076 A EP 17751076A EP 3496611 A1 EP3496611 A1 EP 3496611A1
Authority
EP
European Patent Office
Prior art keywords
light
sensor device
interference
modulation mode
context information
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP17751076.5A
Other languages
German (de)
English (en)
Inventor
Ralph Wilhelm Christianus Gemma Rosa WIJSHOFF
Theodorus Petrus Henricus Gerardus Jansen
Anthonius Petrus Gerardus Emanuel Janssen
Joseph Redmond FALLON
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Koninklijke Philips NV
Original Assignee
Koninklijke Philips NV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Koninklijke Philips NV filed Critical Koninklijke Philips NV
Priority claimed from PCT/EP2017/069887 external-priority patent/WO2018029127A1/fr
Publication of EP3496611A1 publication Critical patent/EP3496611A1/fr
Pending legal-status Critical Current

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/72—Signal processing specially adapted for physiological signals or for diagnostic purposes
    • A61B5/7203—Signal processing specially adapted for physiological signals or for diagnostic purposes for noise prevention, reduction or removal
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/145—Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue
    • A61B5/1455—Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue using optical sensors, e.g. spectral photometrical oximeters
    • A61B5/14551—Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue using optical sensors, e.g. spectral photometrical oximeters for measuring blood gases
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/0059—Measuring for diagnostic purposes; Identification of persons using light, e.g. diagnosis by transillumination, diascopy, fluorescence
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/02—Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
    • A61B5/024—Detecting, measuring or recording pulse rate or heart rate
    • A61B5/02416—Detecting, measuring or recording pulse rate or heart rate using photoplethysmograph signals, e.g. generated by infrared radiation
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/72—Signal processing specially adapted for physiological signals or for diagnostic purposes
    • A61B5/7203—Signal processing specially adapted for physiological signals or for diagnostic purposes for noise prevention, reduction or removal
    • A61B5/7207—Signal processing specially adapted for physiological signals or for diagnostic purposes for noise prevention, reduction or removal of noise induced by motion artifacts
    • A61B5/7214—Signal processing specially adapted for physiological signals or for diagnostic purposes for noise prevention, reduction or removal of noise induced by motion artifacts using signal cancellation, e.g. based on input of two identical physiological sensors spaced apart, or based on two signals derived from the same sensor, for different optical wavelengths
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/72—Signal processing specially adapted for physiological signals or for diagnostic purposes
    • A61B5/7228—Signal modulation applied to the input signal sent to patient or subject; demodulation to recover the physiological signal
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B2560/00—Constructional details of operational features of apparatus; Accessories for medical measuring apparatus
    • A61B2560/02—Operational features
    • A61B2560/0242—Operational features adapted to measure environmental factors, e.g. temperature, pollution
    • A61B2560/0247—Operational features adapted to measure environmental factors, e.g. temperature, pollution for compensation or correction of the measured physiological value
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B2560/00—Constructional details of operational features of apparatus; Accessories for medical measuring apparatus
    • A61B2560/02—Operational features
    • A61B2560/0266—Operational features for monitoring or limiting apparatus function
    • A61B2560/0276—Determining malfunction
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/68—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient
    • A61B5/6801—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient specially adapted to be attached to or worn on the body surface
    • A61B5/6813—Specially adapted to be attached to a specific body part
    • A61B5/6825—Hand
    • A61B5/6826—Finger

Definitions

  • the present invention relates to a sensor device for sensing physiological information of a subject. Further, the present invention relates to a device for communication with a sensor device for monitoring physiological information of a subject. Still further, the present invention relates to corresponding methods.
  • Pulse oximetry is widely applied to measure pulse rate (PR), oxygen saturation (Sp02) or other physiological information (also called vital signs).
  • Pulse oximeters (or, more generally, sensor devices) are used in hospitals, but also in ambulatory settings, e.g., at home.
  • Pulse oximeters make use of the optical technology called photoplethysmography (PPG).
  • PPG measures cardiac-induced changes in arterial blood volume by emitting light through tissue.
  • a pulse oximeter uses multiple light sources to obtain PPG signals at least at two different wavelengths. These light sources are multiplexed / modulated to measure the PPG signals with a single photodiode.
  • the light modulation schemes of pulse oximeters are static and have been designed to prevent interference from 50 Hz and 60 Hz mains components and their harmonics.
  • mains frequency based electronic light dimming and new light sources such as LED lighting, and modulated lighting systems, which encode information in the light, cause interference at other frequencies than the frequencies related to mains.
  • the frequency of the interference can change over time, e.g., when it depends on specific settings of a lamp such as the amount of dim. Therefore, the conventional schemes cannot suppress interference from new lighting solutions.
  • WO 2011/1 17780 Al discloses measuring the interfering light frequencies by adding a dark channel, i.e., measuring the photodiode current with the LEDs switched off. Via adaptive filtering the ambient light interference in each of the PPG signals can then be suppressed to some extent. However, such an adaptive filter will not completely remove the interference.
  • WO 2009/153700 Al discloses measuring the ambient light interference via spectral analysis and adjusting the Time Domain Multiplexing (TDM) or Frequency Domain Multiplexing (FDM) modulation schemes accordingly to avoid using the spectral ranges which are polluted by ambient light interference.
  • TDM Time Domain Multiplexing
  • FDM Frequency Domain Multiplexing
  • WO 201 1/011730 Al discloses a system for detecting and calculating the level of ambient and/or environmental noise, such as electromagnetic interference generated by electric power lines, ambient lights, light dimmers, television or computer displays, power supplies or transformers, and medical equipment.
  • the system comprises a monitor and a sensor.
  • the system performs frequency analysis on the interference signal detected by light photodetectors and determines the power of the interference signal concentrated in the analyzed frequency bands.
  • the worst-case interference level can be determined by selecting the maximum from the computed power values.
  • the determined interference signal power can be compared with the noise tolerance of a patient monitoring system configured to reliably and non- invasively detect physiological parameters of a user.
  • the modulation, demodulation and processing is performed in the monitor.
  • a sensor device for sensing physiological information of a subject comprising
  • a communication unit for receiving, from an external source, context information indicating one or more of
  • spectral information indicating an ambient light spectrum, said spectral information allowing the sensor device to determine the modulation mode and/or settings of an interference reduction algorithm
  • one or more light emitters for emitting modulated light onto the tissue of the subject
  • a light detector for detecting light which is transmitted through the tissue or/and which is reflected from the tissue
  • a light modulator for modulating light in accordance with the modulation mode indicated by or determined from the received context information and a light demodulator for demodulating the detected light in accordance with the modulation mode used by the light modulator for modulating light and/or
  • a processing unit for performing an interference reduction algorithm for reducing ambient light interference with settings indicated by or determined from the received context information.
  • a device for communication also called “communication device” hereinafter
  • a sensor device for monitoring physiological information of a subject comprising
  • a context information obtaining unit for obtaining context information indicating one or more of
  • a communication unit for transmitting to the sensor device the obtained context information.
  • the present invention is based on the idea to receive, instead of to measure the interference spectrum itself, information about interference and the optimum modulation mode (sometimes also called modulation scheme) to use from an external source, e.g. the proposed device for communication with the sensor device, to which it is connected via a (wired or wireless) communication channel.
  • the information may hereby be received in advance so that the sensor device can be preconfigured in a particular setting, or the information may be received as a current measurement to directly set the sensor device in a favorable modulation mode.
  • the received context information may include modulation information indicating a modulation mode, i.e. the external source determined the best modulation mode, e.g., from measured spectral information. Additionally or instead, the received context information may include spectral information indicating an ambient light spectrum, said spectral information allowing the sensor device to determine the modulation mode. Further, the received context information may include settings of an interference reduction algorithm and/or sensor type information. For instance, an adaptive filtering scheme may be applied, as example of an interference reduction algorithm, to remove the interference.
  • the sensor type provides information about the achievable performance, which could be recorded in a table with achievable thresholds for specific sensor types.
  • Receiving and using such context information can be more power efficient compared to known methods.
  • Preconfiguring a sensor device with the interference spectra present is most power efficient.
  • the lighting conditions may be changed to enable reliable measurements.
  • photoplethysmography system can receive ambient light interference information from multiple systems, e.g., a pulse oximeter or a sports watch with an optical heart rate measurement), a communication channel through which the various devices / systems can communicate with each other.
  • multiple systems e.g., a pulse oximeter or a sports watch with an optical heart rate measurement
  • a communication channel through which the various devices / systems can communicate with each other.
  • the sensor device may further comprise a processing unit for determining a vital parameter of a subject from the demodulated light.
  • the vital parameter e.g., pulse rate, Sp02, etc.
  • the sensor device itself can determine the desired vital parameter.
  • the determined vital parameter can then be shown on a small display, or transmitted to a patient monitor or a measurement module or a (caregiver's) user device for display, or to any other extemal entity for further use.
  • the sensor device may further comprise a processing unit for determining from the received spectral information the modulation mode and/or settings of an interference reduction algorithm, for which ambient light interference is minimized or is below a predetermined threshold or a threshold determined from the context information such as the sensor type.
  • the sensor device itself determines the optimum modulation mode or interference reduction algorithm.
  • the threshold is preferably determined in advance, e.g. by simulations or measurements.
  • the threshold may e.g. be set in absolute units or related to the level of the physiological signal of interest.
  • the sensor type which is applied to the patient can be determined or this information can be obtained as part of the context information. Further, with this embodiment the threshold can be adjusted dependent on the known ambient shielding performance or "ambient light sensitivity" of the applied sensor.
  • the light detector which may e.g. be a photodiode, may be configured to measure the ambient light spectrum while no light is emitted by said light emitter, which may e.g. be an LED, and the sensor device may further comprise a processing unit for determining from the measured ambient light spectrum the modulation mode and/or settings of an interference reduction algorithm, for which ambient light interference is minimized or is below a
  • predetermined threshold or a threshold determined from the context information such as the sensor type This enables the sensor device to verify or adjust any received context information like modulation and spectrum information based on actual and up-to-date measurements made by the sensor device itself, which exactly reflect the potential interference at the location of the sensor device.
  • said light detector is configured to measure the ambient light spectrum while no light is emitted by said light emitter
  • said communication unit is configured to transmit further spectral information indicating the measured ambient light spectrum to an external entity, e.g. a patient monitor.
  • the determination of the optimum modulation mode and/or settings of an interference reduction algorithm may thus be done by the external entity and may then be communicated to the sensor device, which thus does not require using power to analyze the spectral information.
  • a processing unit may still be required to determine the spectrum, or efficiently communicate the measured data, or determine a physiological parameter.
  • the sensor device may further comprise a processing unit for determining if sufficient bandwidth is available for emitting light by the light emitter with ambient light interference below a predetermined threshold, possibly after application of an interference reduction algorithm.
  • the sensor device may further comprise an alarm unit for issuing an alarm if it is determined that insufficient bandwidth is available for emitting light by the light emitter with ambient light interference below a predetermined threshold, possibly after application of an interference reduction algorithm.
  • An exemplary sufficient bandwidth may be e.g. 10-30 Hz centered around a carrier frequency depending on the type of application.
  • said processor may be configured to determine if ambient light interference is below a threshold and to set said threshold in accordance with the sensor type information.
  • the sensor type information may include information whether it is a transmissive or reflective sensor, the amount of shielding for ambient light, information about the site (e.g. finger, forehead, earlobe, nasal septum, alar wing, foot, etc.), information about the patient category (e.g. neonate, child, adult) and/or information about the manufacturer and the model.
  • the various processing units of the sensor device may be implemented by the same or different elements and may use hardware, software or a combination of soft- and hardware, e.g. a programmed processor.
  • the device for communication (also called communication device herein) with the above described sensor device comprises a context information obtaining unit for obtaining (i.e. acquiring, receiving or retrieving) context information indicating one or more of a modulation mode, settings of an interference reduction algorithm, sensor type information, and spectral information indicating an ambient light spectrum, said spectral information allowing the sensor device or the communication device to determine the modulation mode and/or settings of an interference reduction algorithm.
  • the communication device comprises a context information obtaining unit for obtaining (i.e. acquiring, receiving or retrieving) context information indicating one or more of a modulation mode, settings of an interference reduction algorithm, sensor type information, and spectral information indicating an ambient light spectrum, said spectral information allowing the sensor device or the communication device to determine the modulation mode and/or settings of an interference reduction algorithm.
  • the communication device comprises a context information obtaining unit for obtaining (i.e. acquiring, receiving or retrieving) context information indicating one or more of a modulation mode, settings of an interference reduction algorithm
  • the communication device and the sensor device may e.g. be connected wirelessly or in a wired manner, e.g. via a communications network, a computer network, WLAN, Bluetooth, etc., and the communication unit may be adapted accordingly for transmitting the desired information to the sensor device.
  • the context information obtaining unit comprises a light detector, e.g. a photodiode, for detecting an ambient light spectrum and the communication device further comprises an analysis unit for analyzing the detected ambient light spectrum and generating said context information.
  • a light detector e.g. a photodiode
  • the communication device further comprises an analysis unit for analyzing the detected ambient light spectrum and generating said context information.
  • the communication device may further comprise a processing unit for determining from the obtained context information the modulation mode and/or the settings of an interference reduction algorithm, for which ambient light interference is minimized or is below a predetermined threshold.
  • Said processing unit may further be configured to take previously obtained spectral information and/or a previously determined modulation mode and/or previously determined settings of an interference reduction algorithm into account in determining the modulation mode and/or the settings of an interference reduction algorithm. This further improves the determination of the modulation mode and/or the settings of an interference reduction algorithm, i.e. the processing unit may be configured as a learning system.
  • the communication device may further comprise a processing unit for determining if sufficient bandwidth is available for emitting light by the light emitter of the sensor device with ambient light interference below a predetermined threshold, possibly after application of an interference reduction algorithm, and an alarm unit for issuing an alarm if it is determined that insufficient bandwidth is available for emitting light by the light emitter of the sensor device with ambient light interference below a predetermined threshold, possibly after application of an interference reduction algorithm.
  • a processing unit for determining if sufficient bandwidth is available for emitting light by the light emitter of the sensor device with ambient light interference below a predetermined threshold, possibly after application of an interference reduction algorithm
  • an alarm unit for issuing an alarm if it is determined that insufficient bandwidth is available for emitting light by the light emitter of the sensor device with ambient light interference below a predetermined threshold, possibly after application of an interference reduction algorithm.
  • a caregiver or other staff may be informed to take measures to change the ambient lighting conditions to make sure that measurements can be taken with less ambient light interference, or to replace the sensor by a sensor which has better shielding
  • the communication device is a lighting apparatus
  • said context information obtaining unit comprises an interface for receiving or measuring the emission spectrum of the lighting apparatus and generating said context information (in particular spectral information) from said emission spectrum.
  • the lighting apparatus generally knows its own emission spectrum and can thus forward this information so that the spectral information or other context information (e.g., modulation information) can be determined in an easy but accurate manner.
  • said context information obtaining unit is configured to receive spectral information indicating an ambient light spectrum from said sensor device or from a light detector.
  • the various processing units of the communication device may be implemented by the same or different elements and may use hardware, software or a combination of soft- and hardware, e.g. a programmed processor.
  • Fig. 1 shows a typical setup for transmission pulse oximetry
  • Fig. 2 shows a schematic diagram of a first embodiment of a sensor device, in particular for transmission pulse oximetry, and a communication device according to the present invention
  • Fig. 3 shows a demodulator with a periodic square wave reference signal
  • Fig. 4 shows a schematic diagram of a second embodiment of a sensor device and a communication device according to the present invention
  • Fig. 5 shows a schematic diagram of a third embodiment of a sensor device and a communication device according to the present invention
  • Fig. 6 shows a schematic diagram of a fourth embodiment of a sensor device and a communication device according to the present invention
  • Fig. 7 shows a schematic diagram of a fifth embodiment of a sensor device and a communication device according to the present invention
  • Fig. 8 shows a schematic diagram of a sixth embodiment of a sensor device and a communication device according to the present invention
  • Fig. 9 shows a schematic diagram of a seventh embodiment of a sensor device and a communication device.
  • Fig. 1 shows a typical setup for transmission pulse oximetry:
  • a red light source 1 and a near-infrared (IR) light source 2 are used for irradiating red light of, e.g. 660 nm, and near- IR light of, e.g. 940 nm, onto tissue of a patient, i.e. onto a finger 3.
  • the part of the light which is transmitted through the finger 3 is then collected with a common light detector 4, e.g. a photodiode.
  • More than two wavelengths, e.g. four, eight or twelve wavelengths, may be used as well in pulse oximetry.
  • Fig. 2 depicts a general block diagram of a transmission pulse oximeter, as an example of a sensor device 100, according to a first embodiment of the present invention.
  • the sensor device 100 comprises a processing unit 5 that adjusts the parameters of a light modulator 6 which acts a pulse controller and modulates the light sources 1 , 2.
  • the configuration of the light modulator 6 depends on the specific multiplexing scheme applied, e.g. in case of TDM the light sources 1, 2 are activatedissematingly whereas for FDM the light sources 1, 2 radiate light with different modulation frequencies. In case of FDM, the light sources can also simultaneously radiate light with different modulation frequencies, but this requires the light sources not to be configured anti-parallel.
  • the reason for the multiplexing scheme is that in this way the same light detector 4 can be used to estimate the attenuation of the light from both light sources 1, 2.
  • the light detector 4 detects the light that has propagated through the medium of the finger 3 and converts it into an electrical signal. This signal is then pre-processed by a signal- conditioning block 8, which comprises analog amplifiers and filters, which make the signal suitable for conversion to the digital domain by an analog-to-digital converter (ADC) 9.
  • ADC analog-to-digital converter
  • Correlators 10 each comprising a demodulator 11 and a demultiplexer 12, are used to simultaneously demodulate and demultiplex the detected light, and the results are presented to the processing unit 5, which determines the parameters of interest by evaluating the transmitted and demodulated signals.
  • the sensor device 100 comprises a communication unit 7 for receiving context information indicating the modulation mode, settings of an interference reduction algorithm, sensor type information, and/or spectral information indicating an ambient light spectrum, said spectral information allowing the sensor device 100 to determine the modulation mode or to determine the filtering scheme to reduce the interference.
  • This information is received from a communication device 200, which may e.g. be a patient monitor or a lighting apparatus.
  • the communication device 200 particularly comprises a context information obtaining unit 20 for obtaining context information, e.g. spectral information indicating an ambient light spectrum, and a communication unit 21 for transmitting to the sensor device the context information.
  • the sensor device 100 can e.g. use a modulation mode being provided to the sensor device 100 for modulating light in accordance with the modulation mode.
  • the sensor device 100 can use the context information to determine the optimum filtering scheme to reduce the interference.
  • the modulation mode used according to the various embodiments of the present invention is independent of the specific multiplexing technique applied, since all attenuation measurement methods incorporate a certain modulation method.
  • the description of the following embodiments is restricted to a single light source, as may also be used in an embodiment of the proposed sensor device, thereby disregarding the specific demultiplexing method.
  • a single light source only one correlator 10 is necessary. This correlator 10 then simply equals a demodulator 1 1, such as depicted in Fig. 3.
  • the square wave shown in Fig. 3 is only illustrative, as any periodic signal can be applied to both modulate the light sources 1, 2 and demodulate the received signal as long as the fundamental frequencies and/or harmonics coincide.
  • the sensor device may be configured, instead of a pulse oximeter, as another type of device with a photoplethysmograph, such as a sports watch, a heart rate measuring device, a wearable device, a smartphone etc. with an optical measurement for sensing physiological information of a subject, such as a patient, a person doing sports, a neonate, etc., or of an animal such as a pet.
  • FIG. 4 A second embodiment of a communication device 201 is illustrated in Fig. 4, which is implemented as a patient monitor in this embodiment.
  • the patient monitor 201 comprises a photodiode 22 (in general a light detector), e.g. as an implementation of the spectral information obtaining unit 20.
  • An analyzer 23 analyses the ambient light spectrum and finds a suitable part in the spectrum containing the required bandwidth with a minimum amount of ambient light interference, possibly after the application of an interference reduction algorithm. Based on the analysis the processing unit 24 determines the most appropriate modulation mode to use with the optimal parameters, optionally also taking into account previously measured interference spectra (i.e. spectral history).
  • the communication unit 21 transmits (e.g. broadcasts) a message to selected or, preferably, all sensor devices (e.g. pulse oximeters and/or other sensor devices) in the vicinity e.g. in the same room, containing the context information, e.g. including instructions of the optimal modulation mode which should be selected and executed by the sensor devices.
  • the processing unit 24 can determine the optimum parameters of an interference reduction algorithm, which settings are also transmitted by communication unit 21.
  • the patient monitor 201 can perform ambient light spectral analysis on short intervals, e.g., every 0.5 s. Measurement of ambient light can be performed using, e.g., a photodiode positioned on top of the patient monitor or next to the display of the patient monitor.
  • a patient monitor 201 can remain in the same room, it can keep a history of ambient light spectra, for instance in the analysis unit 23. In this way, the patient monitor 201 can also store the interference from, e.g., a reading light which is only switched on occasionally. By taking into account the history in the determination of the most suitable modulation mode, the patient monitor can prevent disturbances from light sources which are switched on only occasionally.
  • the patient monitor 201 can issue a visual and/or audible interference alarm by an optional alarm unit 25.
  • the communication device e.g. a patient monitor
  • the individual sensor devices do not have to use power for the ambient light spectral analysis, and only have to receive instructions from the communication device, which is e.g. powered by mains. It would be a waste of resources if all battery-powered sensor devices in a room individually analyze the ambient light spectrum, all arriving at the same conclusion, as exposure to ambient light is an overall environmental condition holding for all sensor devices in a room.
  • a third embodiment of a communication device 202 is illustrated in Fig. 5, which is implemented as a dedicated small device that is e.g. placed in and powered by a wall socket.
  • This small device 202 comprises a light detector 22 and an analysis unit 23, like the patient monitor 201 to determine the most appropriate modulation mode to use given the ambient light spectrum.
  • the processing unit 24 determines the optimum modulation parameters such as the repetition frequency in a Time Division Multiplexing scheme, the frequencies of operation in a Frequency Division Multiplexing scheme, or the modulation frequency of a Quadrature
  • the processing unit 24 can determine the optimum parameters of an interference reduction algorithm to reduce the effect of interference below a required level.
  • the modulation mode and optimal parameters are communicated to the sensor devices in the vicinity by the communication unit 21. This solution could be attractive in, e.g., a hallway, where ambulant patients are passing by with a wearable battery-powered sensor solution.
  • a fourth embodiment of a communication device 203 and another embodiment of a sensor device 101 are illustrated in Fig. 6.
  • the communication unit 203 is implemented as lighting apparatus (or part of a lighting system).
  • a smart lighting apparatus or a smart lighting system generally knows the (time -varying) emission spectrum that it uses and communicates this to a sensor device, which can receive the emission spectra of multiple smart lighting apparatus and/or systems.
  • the sensor device 101 determines the most appropriate modulation mode with the optimal parameters and/or the optimum parameters of an interference reduction algorithm. If the sensor device 101 is unable to determine a modulation and/or interference reduction which reduces the amount of ambient light interference to a required minimum (i.e.
  • an interference alarm may be issued by an alarm unit 13.
  • a sensor device 102 is illustrated in Fig. 7.
  • the sensor device 102 is pre-configured with the interference spectra present in the environment in which it has been or will be used.
  • the interference spectra could be either obtained from a prior scan performed in the specific environment, or from information provided by the lighting vendors.
  • a transmitting unit 30, which may also be part of a communication device as described above, transmits this information to the sensor device 102.
  • the sensor device 102 can determine the optimal modulation mode or the optimum parameters of an interference reduction algorithm. If no appropriate modulation and/or reduction scheme can be found, the sensor device (e.g. pulse oximeter) or patient monitor may issue an interference alarm as described above.
  • FIG. 8 A still further embodiment of a communication device 204 and of a sensor device 103 is illustrated in Fig. 8.
  • the ambient light measurement is performed by the photodiode 4 of the sensor device 103, which can for instance be done at start-up of the sensor device 103, or periodically while the sensor device 103 is operational.
  • the sensor device e.g. pulse oximetry module
  • the analysis of the ambient light spectrum and the subsequent selection and adjustment of the modulation mode and/or an interference reduction algorithm is done by the communication device 204, e.g. implemented as patient monitor.
  • the analysis unit 23 of the communication device 204 analyses the ambient light spectrum and finds a suitable part in the spectrum containing the required bandwidth with a minimum amount of ambient light interference, possibly after interference reduction by an interference reduction algorithm with optimally selected parameters.
  • the processing unit 24 determines the most appropriate modulation mode and/or interference reduction algorithm to use with the optimal parameters, also taking into account previously measured interference spectra.
  • the communication device 21 transmits (e.g. broadcasts) a message to selected or, preferably, all sensor devices in the room, containing the instructions of the optimal modulation mode and/or interference reduction algorithm which should be selected and executed by the sensor device(s).
  • An interference reduction algorithm may in the simplest form be a low-pass filter which is applied to the demodulated PPG signals. If necessary, the cut-off frequency can be reduced to reduce interference near the pulse frequency components. The cut-off frequency can be part of or derived from the context information. Another example of an interference reduction algorithm is a notch filter which removes frequency components at one or more interfering frequencies specified by the context information. Still another example is an adaptive algorithm that estimates the interference present in the (de)modulated signal and subtracts the interference estimate to reduce the interference.
  • the context information may include sensor type information.
  • sensor type information are information about whether the sensor is a transmissive or reflective sensor, about the sensor site (e.g. finger, forehead, earlobe, nasal septum, alar wing, foot), about the patient category (e.g. neonate, child, adult), about the manufacturer and model, etc.
  • the sensor type information may thus be used to get information about the achievable performance, which could be stored in a table with achievable thresholds for specific sensor types.
  • the sensor could thus e.g. set thresholds accordingly, i.e. use threshold that are adapted to the sensor type.
  • the light modulator 6 and the light demodulator 1 1 are part of the sensor device.
  • the light modulator 6 and the light demodulator 11 are part of the communication device.
  • This is schematically illustrated in Fig. 9 showing a corresponding embodiment of a communication device 205 and another embodiment of a sensor device 104.
  • the sensor device 104 merely comprises the light emitters 1 , 2 and the light detector 4, whereas all other elements including the light modulator 6 and the light demodulator 1 1 are included in the communication device 205.
  • Communication units (7, 21) as provided in the other embodiments are not necessarily required in this embodiment.
  • the modulated drive currents of the light emitters 1, 2 are transmitted from the communication device 205 to the sensor device 104 via a connecting wire 40, and the detection signals of the light detector 4 are transmitted from the sensor device 104 to the communication device 205 via a connecting wire 41.
  • the communication device 205 may further comprise a processing unit for performing an interference reduction algorithm for reducing ambient light interference with settings indicated by or determined from the received context information and/or for processing the detected light in accordance with the sensor type information.
  • the light modulation/demodulation and/or the processing may either be performed in the sensor device or in the communication device.
  • a communication device such as a patient monitor
  • the monitor can also store the interference from, e.g., a reading light which is only switched on occasionally.
  • communication device can prevent disturbances from light sources which are switched on only occasionally.
  • a communication device would be a smartphone or tablet, as coded light for example is specifically designed to be received by these devices.
  • Sensor devices to perform for example spot-check measurements having communication means to connect to smartphones are widely available. By presetting the modulation based on context information gathered by the mobile device it connects to, the battery life or the number of spot- checks that can be performed on a single charge or battery could be improved in the end possibly resulting in again even smaller devices.
  • the present invention generally applies to all sensor devices, in particular pulse oximetry and photoplethysmography solutions, ranging from hospital sensors (such as hospital pulse oximeters), wearable sensors (such as wearable pulse oximeters, e.g. for telemetry or ambulatory monitoring), (sports) watches with optical heart rate technology, etc.
  • hospital sensors such as hospital pulse oximeters
  • wearable sensors such as wearable pulse oximeters, e.g. for telemetry or ambulatory monitoring
  • sports watches with optical heart rate technology, etc.
  • one embodiment of the present invention is directed to a sensor device for sensing physiological information of a subject comprising
  • a communication unit for receiving, from an external source, context information indicating one or more of
  • one or more light emitters for emitting modulated light onto the tissue of the subject
  • a light detector for detecting light which is transmitted through the tissue or/and which is reflected from the tissue
  • a light modulator for modulating light in accordance with the modulation mode indicated by or determined from the received context information and a light demodulator for demodulating the detected light in accordance with the modulation mode used by the light modulator for modulating light.
  • a communication unit for receiving, from an external source, context information indicating one or more of
  • one or more light emitters for emitting modulated light onto the tissue of the subject, and a light detector for detecting light which is transmitted through the tissue or/and which is reflected from the tissue, and
  • a processing unit for performing an interference reduction algorithm for reducing ambient light interference with settings indicated by or determined from the received context information.
  • the sensor device comprises such a light modulator and such a processing unit.
  • a computer program may be stored/distributed on a suitable non-transitory medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems.
  • a suitable non-transitory medium such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems.

Landscapes

  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Health & Medical Sciences (AREA)
  • Pathology (AREA)
  • Biomedical Technology (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Medical Informatics (AREA)
  • Molecular Biology (AREA)
  • Surgery (AREA)
  • Animal Behavior & Ethology (AREA)
  • Biophysics (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Signal Processing (AREA)
  • Physiology (AREA)
  • Artificial Intelligence (AREA)
  • Computer Vision & Pattern Recognition (AREA)
  • Psychiatry (AREA)
  • Cardiology (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Optics & Photonics (AREA)
  • Measurement Of The Respiration, Hearing Ability, Form, And Blood Characteristics Of Living Organisms (AREA)
  • Measuring Pulse, Heart Rate, Blood Pressure Or Blood Flow (AREA)

Abstract

La présente invention concerne un dispositif portatif pour l'acquisition d'information physiologique d'un sujet. Afin d'éviter, ou de réduire efficacement l'interférence ambiante, le dispositif de détection comprend une unité de communication (7) destinée à recevoir, en provenance d'une source externe, des informations de contexte indiquant un, ou plusieurs mode de modulation, des réglages d'un algorithme de réduction d'interférence et des informations spectrales indiquant un spectre de lumière ambiante. Les informations spectrales permettant au capteur de déterminer le mode de modulation et/ou les réglages d'un algorithme de réduction des interférences, un ou plusieurs émetteurs de lumière (1, 2) pour émettre de la lumière modulée sur le tissu du sujet, et un détecteur de lumière (4) pour détecter la lumière qui est transmise à travers le tissu et/ou qui est réfléchie par le tissu. Le dispositif de détection comprend un modulateur de lumière (6), pour moduler la lumière selon le mode de modulation indiqué par, ou déterminé à partir des informations de contexte reçues, et un démodulateur de lumière (11) pour démoduler la lumière détectée selon le mode de modulation utilisé par le modulateur de lumière, pour moduler la lumière et/ou une unité de traitement (5), pour réaliser un algorithme de réduction d'interférence et réduire l'interférence de lumière ambiante avec des réglages indiqués par, ou déterminés à partir des informations de contexte reçues.
EP17751076.5A 2016-08-12 2017-08-07 Dispositif de capteur et procédé, dispositif et procédé de communication avec le dispositif de capteur. Pending EP3496611A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US201662374031P 2016-08-12 2016-08-12
EP16186224 2016-08-30
PCT/EP2017/069887 WO2018029127A1 (fr) 2016-08-12 2017-08-07 Dispositif de capteur et procédé, dispositif et procédé de communication avec le dispositif de capteur.

Publications (1)

Publication Number Publication Date
EP3496611A1 true EP3496611A1 (fr) 2019-06-19

Family

ID=59579627

Family Applications (1)

Application Number Title Priority Date Filing Date
EP17751076.5A Pending EP3496611A1 (fr) 2016-08-12 2017-08-07 Dispositif de capteur et procédé, dispositif et procédé de communication avec le dispositif de capteur.

Country Status (4)

Country Link
US (1) US11793466B2 (fr)
EP (1) EP3496611A1 (fr)
JP (1) JP7261736B2 (fr)
CN (1) CN109561860A (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110132323A (zh) * 2019-04-23 2019-08-16 深圳市志奋领科技有限公司 一种环境光干扰的消除方法及装置

Family Cites Families (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5588427A (en) 1995-11-20 1996-12-31 Spacelabs Medical, Inc. Enhancement of physiological signals using fractal analysis
JP2006523843A (ja) * 2003-04-15 2006-10-19 センサーズ・フォー・メデセン・アンド・サイエンス・インコーポレーテッド 光センサーに対する周辺光の影響を減じるための装置及び方法
JP2005124903A (ja) 2003-10-24 2005-05-19 Fukuda Denshi Co Ltd 生体情報モニタ、セントラルモニタ及び患者監視システム
US20070230941A1 (en) 2006-03-29 2007-10-04 Alton Smith Device and method for detecting ambient light
US8064975B2 (en) * 2006-09-20 2011-11-22 Nellcor Puritan Bennett Llc System and method for probability based determination of estimated oxygen saturation
US20080167541A1 (en) * 2007-01-09 2008-07-10 Panu Takala Interference Suppression in Spectral Plethysmography
US20090069642A1 (en) * 2007-09-11 2009-03-12 Aid Networks, Llc Wearable Wireless Electronic Patient Data Communications and Physiological Monitoring Device
WO2009153700A1 (fr) 2008-06-16 2009-12-23 Koninklijke Philips Electronics N.V. Surveillance d'un paramètre vital d'un patient avec un schéma de modulation « in situ » pour éviter une interférence
US8504130B2 (en) 2008-10-07 2013-08-06 Covidien Lp Non-interfering physiological sensor system
US8401602B2 (en) * 2008-10-13 2013-03-19 Masimo Corporation Secondary-emitter sensor position indicator
US8471713B2 (en) * 2009-07-24 2013-06-25 Cercacor Laboratories, Inc. Interference detector for patient monitor
EP2549926A1 (fr) 2010-03-23 2013-01-30 Koninklijke Philips Electronics N.V. Réduction d'interférence dans la surveillance d'un paramètre vital d'un patient
US20120136257A1 (en) * 2010-11-30 2012-05-31 Nellcor Puritan Bennett Llc SNR Through Ambient Light Cancellation
US20120203491A1 (en) * 2011-02-03 2012-08-09 Nokia Corporation Method and apparatus for providing context-aware control of sensors and sensor data
US9044171B2 (en) * 2012-06-22 2015-06-02 Fitbit, Inc. GPS power conservation using environmental data
US9910828B2 (en) * 2013-03-12 2018-03-06 Qualcomm Incorporated Spectrometer for personal context
US20150018649A1 (en) * 2013-07-15 2015-01-15 Covidien Lp Methods and systems for using a differential light drive in a physiological monitor
US20150031971A1 (en) * 2013-07-26 2015-01-29 Covidien Lp Methods and systems for using an estimate signal to improve signal resolution in a physiological monitor
US20150148632A1 (en) * 2013-11-26 2015-05-28 David Alan Benaron Calorie Monitoring Sensor And Method For Cell Phones, Smart Watches, Occupancy Sensors, And Wearables
JP2015173935A (ja) * 2014-03-18 2015-10-05 セイコーエプソン株式会社 生体計測装置および生体計測方法
US9668698B2 (en) * 2014-04-03 2017-06-06 Koninklijke Philips N.V. Monitoring device and method for compensating non-linearity effects in vital signs monitoring
US10656009B2 (en) * 2014-07-16 2020-05-19 Verily Life Sciences Llc Context discrimination using ambient light signal
US10420515B2 (en) * 2015-06-15 2019-09-24 Vital Labs, Inc. Method and system for acquiring data for assessment of cardiovascular disease

Also Published As

Publication number Publication date
US20190175116A1 (en) 2019-06-13
JP2019527595A (ja) 2019-10-03
JP7261736B2 (ja) 2023-04-20
CN109561860A (zh) 2019-04-02
US11793466B2 (en) 2023-10-24

Similar Documents

Publication Publication Date Title
EP3488776A1 (fr) Dispositif portable utilisant un capteur ppg pour communication optique
US9462976B2 (en) Methods and systems for determining a probe-off condition in a medical device
EP2958485B1 (fr) Marqueur doté d'une zone émettrice de lumière destiné à être utilisé dans la détermination d'informations de signes vitaux
US10656009B2 (en) Context discrimination using ambient light signal
US8447372B2 (en) Monitoring a vital parameter of a patient with “in-situ” modulation scheme to avoid interference
US20140243633A1 (en) Methods and systems for determining a probe-off condition in a medical device
US20140221847A1 (en) System and method for determining vital sign information of a subject
Cahyadi et al. Patient monitoring using visible light uplink data transmission
US9220409B2 (en) Optical instrument with ambient light removal
US20190046121A1 (en) Multi-Vital-Sign Smartphone System in an Electronic Medical Records System
US20140175261A1 (en) Methods and systems for detecting a sensor-off condition using interference components
US20150018649A1 (en) Methods and systems for using a differential light drive in a physiological monitor
US20140180042A1 (en) Methods and Systems for Detecting a Sensor Off Condition Using A Reference Ambient Characteristic
JP6069813B1 (ja) バイタルサイン監視における非線形性効果を補償する監視デバイス及び方法
US11793466B2 (en) Sensor device and method, device and method for communication with the sensor device
US11412989B2 (en) Sensor device and method for sensing physiological information of a subject
CN102811663A (zh) 监测患者生命参数时的干扰减小
WO2018029127A1 (fr) Dispositif de capteur et procédé, dispositif et procédé de communication avec le dispositif de capteur.
US20140275882A1 (en) Methods and Systems for Determining a Probe-Off Condition in a Medical Device
Ekhare et al. Design and Development of Low Unit Cost and Longer Battery Life Wireless Pulse Oximetry System
US11633116B2 (en) System and method for interference and motion detection from dark periods

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: UNKNOWN

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20190312

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

DAV Request for validation of the european patent (deleted)
DAX Request for extension of the european patent (deleted)
RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: KONINKLIJKE PHILIPS N.V.

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: EXAMINATION IS IN PROGRESS

17Q First examination report despatched

Effective date: 20220407